1. Field of the Invention
This invention relates to a door stopper for preventing an open door from hitting a wall and which is used to keep a door open, as well as to a method for raising and lowering the door stopper.
2. Description of the Related Art
As related art of a door stopper such as that described above, art is known which has a structure having a short post at a corner portion defined by a wall and the floor, the tip of which is provided with a cushioning body for the door, and a hook for keeping the door open. However, this type of related art of a door stopper gets in the way when a floor polisher is used because the post is always protruding from the floor. Furthermore, because it is an obstruction for wheelchairs and the like, it is unsuitable for use in barrier free housing.
An object of the present invention is to provide a door stopper which solves the foregoing problems, is suitable for use in barrier free housing without becoming an obstruction to floor polishers and wheelchairs, and which functions to prevent an open door from hitting the wall and to keep a door open.
In order to solve the foregoing problems, the door stopper of the first aspect of the present invention is provided with a guide cylinder, sunk vertically into the floor, and a door contacting member able to be set in two positions, in a door contacting state in which it protrudes above the floor and in a housed state in which the top is substantially level with the floor. This construction enables the floor to be substantially flat when the door stopper is not in use so that it does not become an obstruction to floor polishers and wheelchairs.
In a preferred embodiment of the present invention, the door contacting member is constantly being forced upward by a spring disposed between the door contacting member and the guide cylinder. Moreover, a lock mechanism is provided which keeps the door lock in a housed state. This lock mechanism is preferably constructed from a pin provided in the guide cylinder and a grooved cam which is formed on the door contacting member and which engages with the pin. The grooved cam can be a heart-shaped grooved cam with a step to prevent pin reversal and the lock mechanism can be shaped so as to have horizontal portions at the top and bottom of a vertical groove. Employing this type of lock mechanism enables the door contacting member to be set in two positions, in a door contacting state with the door contacting member and in a housed state, with a simple operation.
Furthermore, in a preferred embodiment of the present invention, the structure can be such that a vertical space is formed between the door contacting member and the guide cylinder, and a closing body that closes the upper end of this space is attached to the upper portion of the guide cylinder. Accordingly, dust is able to be prevented from entering, and even if dust does get into the inner portion, it can fall out the bottom of the guide cylinder, thereby making the door stopper durable.
Moreover, as a separate embodiment of the present invention, in a method for raising and lowering the door stopper, the door contacting member is inserted into the guide cylinder sunk vertically into the floor so as to keep the door contacting member in a state wherein the top thereof is substantially the same level as the floor. With this method, the floor can be substantially flat when the door stopper is not in use so that it does not become an obstruction to floor polishers and wheelchairs.